It´s not always easy to do. Very few things that are worthwhile ARE easy. However, if you´ve betrayed someone´s trust, think about what you´ve done. Explain to your partner that you are truly sorry for that betrayal.

The shattering of trust is perhaps the most brutal thing you can do to another person. Admitting your remorse is a step towards starting to repair the damage. You´ll probably have to do it a few times before your partner starts to believe you, but saving the relationship will be well worth it. And in the end, you two will be much stronger because of it.